Reactor liquid circulating pump arrangement

ABSTRACT

A pump circulating a radioactive liquid in a reactor container has a housing including a support tube projecting into the reactor container. A shaft is mounted in the support tube, and has a pump wheel located in the container. The shaft can be lowered so that sealing faces of the pump wheel and support tube abut each other, and communication between container and pump housing is interrupted. In this position, the liquid can be discharged from the pump housing for servicing a motor in the same driving the shaft.

United States Patent Holz et al.

REACTOR LIQUID CIRCULATING PUMP ARRANGEMENT Inventors: Hans Holz; Christian Klepp, both of Frankenthal; Gunter Koll, Fran kenthal-Studernheim, all of Germany Schanzlin Klein 8: Becker Aktiengesellsehaft, Frankenthal/Pfalz. Ger

many

Filed: April 5, 197] App]. No.: 131,168

Assignee;

Foreign Application Priority Data April ll, I970 Germany ..P 2017 415.6

US. Cl. ..417l360, 222/333, 310/54,

Int. Cl.....F04b 17/00, F04b 35/00, GOlf 11/06, GOlf 11/30, H02k 9/00, H02k 9/20 Field of Search ..4l7/424, 423, 360, 36l, 372; 222/333; 415/201; 3 l0/S4 1451 Dec. 19, 1972 [56] References Cited UNITED STATES PATENTS 2,384,254 9/1945 Meredew ..4l5/20l X 3,625,639 12/1971 Eggmann et al ..4l7/36() Primary Examiner-Robert M. Walker Azt0rneyMichael S. Striker [57] ABSTRACT A pump circulating a radioactive liquid in a reactor container has a housing including a support tube projecting into the reactor container. A shaft is mounted in the support tube, and has a pump wheel located in the container. The shaft can be lowered so that sealing faces of the pump wheel and support tube abut each other, and communication between container and pump housing is interrupted. [n this position. the liquid can be discharged from the pump housing for servicing a motor in the same driving the shaft 10 Claims, 2 Drawing Figures PATENTED DEC 19 m2 sum 2 or 2 INVENTOR mm mm. BY Nunavut! 600"! to MR 529' REACTOR LIQUID CIRCULATING PUMP ARRANGEMENT BACKGROUND OF THE INVENTION motors cooled by a liquid has not been possible until m now, irrespective of the advantages of such wet motors, since it could not be prevented that some of the radioactive liquid was discharged when the motor was removed for servicing.

SUMMARY OF THE INVENTION It is one object of the invention to provide a pump arrangement for circulating a reactor liquid in which servicing of the motor is possible without loss of radioactive liquid.

Another object of the invention is to provide a pump arrangement in which the pump and motor housing can be emptied of radioactive liquid before the motor is removed from the housing.

Another object of the invention is to provide a pump arrangement in which during normal operation, the liquid in the reactor container also circulates in the pump housing for cooling the motor, but which permits the sealing of the pump and motor housing from the container when servicing of the motor or other parts is required.

In accordance with the invention, a pump shaft is lowered until a seal is formed between the reactor container and the pump housing, whereupon the radioactive liquid is discharged from the pump and motor housing, so that the motor can be removed for servicing.

Preferably, the shaft and its support tube are clamped to each other after emptying of the housing so that the sealing engagement is improved, and it is also possible to remove the shaft with the support tube through the reactor container.

One embodiment of the invention comprises a reactor container for a radioactive cooling liquid; housing means filled with the liquid and including an upper housing portion secured to the container and a support tube projecting upward into the container and having a first annular sealing face; and shaft means mounted in the housing means for rotation and also for limited axial movement.

The shaft means include an upper portion in the support tube having an end portion projecting from the same and including a pump wheel located in the reactor container for moving the liquid. The end portion has a second annular sealing face located above the first sealing face in the normal operative condition of the apparatus. A motor is provided in the lower portion ofthe housing means for driving the lower shaft portion of the shaft means. Holding means are detachably secured to the lower end of the lower housing end portion, and support the lower end of the lower shaft portion in an operative position in which the first and second sealing faces form a circular gap for communication of the liquid in the reactor container with the liquid in the housing means so that the motor is cooled.

When the holding means is withdrawn or removed, the shaft means drops to a lower inoperative position so that the annular sealing face of the shaft means abuts the annular sealing face of the support tube, and communication between the reactor container and the housing means is interrupted. In this condition of the apparatus, the liquid filling the housing means can be discharged, without any discharge of liquid from the reactor container.

A housing space, which is normally closed by covers, permits access to clamping means when the housing is empty and covers are removed. The clamping means clamp the shaft means and the support tube together so that the seal between the annular sealing faces is improved.

Connector means between the upper and lower shaft portions, and other connector means between the upper and lower housing portions, can also be operated in the housing space when the housing has been emptied, so that the entire lower pump housing, with the lower shaft portion and the motor, can be removed from the reactor container.

When the connection between the upper and lower shaft portions is interrupted, and the upper shaft portion is clamped to the support tube, it is possible to withdraw the upper shaft portion with the pump wheel and the support tube in upward direction through the container of the reactor.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a fragmentary sectional view illustrating an embodiment of the invention in a normal operative condition; and

FIG. 2 is a sectional view illustrating the apparatus of FIG. 1 in an inoperative position in which the motor housing is empty, and the interiors of the reactor container and of the housing are sealed from each other.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, a reactor container 9 for a radioactive cooling liquid, is connected by a tubular portion 9a with the upper housing portion 22 of a housing 20 which has a lower housing portion 21 secured by screws 16 to the upper housing portion 22 so that the entire housing 20 is carried by the container 9. The upper housing portion 22 has a shoulder on which the annular shoulder 7b of a support tube 7 rests. A sealing ring 14 is provided around the portion 7a of support tube '7. In this position of support tube 7, screws 19a in a ring 19 secure support tube 7 to the upper housing portion 22.

A shaft 4 is located in the support tube and in housing 20, and has an upper shaft portion 40 located in support tube 7 and rotatably mounted in bearing 17. The end portion of shaft portion 4 projects out of the upper end of support tube 7, and carries a fixed pump wheel 6 which is located in the liquid in container 9, and circulates the same when shaft 4 is rotated. The

upper end of support tube 7 has an annular sealing face cooperating with an annular sealing face 60 of the hub of pump wheel 6. In the normal operative condition shown in FIG. 1, when shoulder 7b of support tube 7 rests on a shoulder of housing means 22, the sealing I faces 60 and 5 are spaced from each other so that a gap is formed permitting entering of radioactive liquid in container 9 through bearing 17 into the annular space in support tube 7 around shaft portion 4a, and further from there into the lower housing portion 21 for cooling motor 15. A housing space 110 in the upper part of the lower housing portion 21 is also filled with the liquid, since large openings 1 lb are closed by covers 11 secured by screws 110.

The upper and lower shaft portions 40, 4b are connected by connector means including screws 18. By opening screws 18, and also connector screws 16 which secure the lower housing portion 21 to the upper housing portion 22, separation between the upper and lower housing portions, and between the upper and lower shaft portions can be obtained. The lower end of the lower shaft portion 41) has a flange 40 resting on a member 8a which is supported by a holding plate 2 secured by screws 1 to the lower end portion of the lower housing portion 21 which is provided with a discharge opening 8. Due to the fact that holding plate 2 supports the shaft 4 in a particular position relative to the housing 20, the sealing face 6a of the pump wheel 6 is spaced from the sealing face 5 of the support tube 7.

The discharge opening 8 is connected by a cooling conduit 25 with an opening lld in one of the covers 11 so that the liquid surrounding motor is cooled. A discharge valve 26 is connected with cooling conduit 25 and discharge opening 8, and is closed during normal operations of the apparatus in the condition shown in FIG. 1.

The upper shaft portion 40 has an annular abutment 13 located in the pump space 110. An annular threaded clamping member 12 has a tubular portion 120 threaded into an inner thread of the end portion 7a of support tube 7. [n the operative position of FIG. 1, the threaded member 12 is adjacent, but spaced from the tubular abutment 13.

When servicing or removal of motor 15 is required, screws 1 are removed, and holding plate 2 withdrawn. Member 80 drops a small distance corresponding to the thickness of the gap 5, 60, but communication of the discharge opening 8 with the interior of housing is maintained. Shaft 4 drops a corresponding distance until the annular sealing face 60 of the pump wheel 6 abuts the annular sealing face 5 at the upper end ofsupport tube 7. In this manner, communication between the container 9 and housing 20 through support tube 7 is interrupted.

Upon opening of discharge valve 26, all the liquid contained in the housing 20, which includes the support tube 7, the upper housing portion 22, and the lower housing portion 21, and also the housing space lla, is discharged, and the housing cannot be filled by the liquid in container 9.

When the housing is empty, the covers 11 are removed after detaching screws 11c. The openings llb are wide enough to permit an operator to turn the threaded clamping member 12 until it abuts the annular abutment 13 of the upper shaft portion 4a. Shaft 4 is thus pulled downward so that the sealing face 60 abuts with great sealing force on the sealing face 5 of the fixed support tube 7. Any leaking between the sealing faces is thus prevented. If any liquid from container 9 should leak into the interior of support tube 7, it may be discharged through a normally closed conduit 10.

It is now possible to open the connector screws 18 so that the upper shaft portion 4a is separated from the lower shaft portion 4b, whereupon the connector screws 16 are removed, so that the lower housing portion 21, together with motor 15 and the lower shaft portion 4b, can be detached while the upper shaft portion 40 remains clamped by clamping member 12 to the stationary upper housing portion 22.

In this manner, motor 15, and other parts in the lower housing portion 21, can be serviced or replaced without any leakage from container 9.

In the event that damage should occur at the upper bearing 17 at the upper end of support tube 7, support tube 7, clamped to the upper shaft portion 4a, can be removed through container 9 after the ring 19, which consists of two semi-circular parts, has been removed with screws 19a.

Screws 19a and ring 19 are accessible since housing space is empty, and the covers 11 removed. If only a repair of the support tube 7 or upper shaft portion 4a is required, the lower housing portion 21 with motor 15 need not be removed.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of reactor pump arrangements differing from the types described above.

While the invention has been illustrated and described as embodied in a pump arrangement for circulating a reactor liquid through a pump and motor housing, and having a servicing condition in which communication between the reactor container and the pump and motor housing is interrupted, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

We claim:

1. Reactor liquid circulating pump arrangement comprising: a reactor container for a radioactive cooling liquid; housing means filled with said liquid, said housing means including a lower housing portion, and an upper housing portion secured to said container, and a support tube projecting upward into said container and having a first annular sealing face in said container; shaft means mounted in said housing means for rotation and also for limited axial movement, said shaft means including an upper portion located in said support tube and having an end portion projecting from said support tube and including a pump wheel located in said reactor container for moving said liquid, said end portion having a second annular sealing face located above said first sealing face, said shaft means having a lower shaft portion located in said lower housing portion of said housing means; a motor in said lower portion of said housing means acting on said lower shaft portion for rotating said shaft means; and holding means detachably secured to the lower end of said lower housing portion and supporting the lower end of said lower shaft portion in an operative position in which said first and second sealing faces form a gap for communication of the liquid in said reactor container with the liquid in said housing means for cooling said motor, said shaft means dropping to a lower inoperative position when said holding means is withdrawn so that said second sealing face abuts said first sealing face and communication between said reactor container and said housing means is interrupted whereby the liquid filling said housing means can be discharged therefrom without discharge of liquid from said reactor container.

2. Pump arrangement as claimed in claim 1 wherein the lower end of said carrier tube has a first abutment surrounding said shaft means; wherein said shaft means has a second abutment below said first abutment; and comprising clamping means operable for forcing said abutments apart when said shaft means is in said in operative dropped position so that said second sealing face is pressed against said first sealing face.

3. Pump arrangement as claimed in claim 1 comprising manually operable means in said housing means acting on the lower end of said support tube and on a part of said upper shaft portion adjacent the same for urging said shaft means downward so that said second sealing face is clamped against said first sealing face.

4. Pump arrangement as claimed in claim 3 wherein said lower end of said support tube has a thread, wherein said part of said upper portion of said shaft means includes an annular abutment, and wherein said manually operated means includes a threaded sleeve surrounding said upper shaft portion, and threaded into said thread of said support tube, said sleeve being turnable to a position abutting said annular abutment in said inoperative position of said shaft means so that said shaft means is clamped to said support tube while said shaft means is in said inoperative position and said second sealing face is pressed against said first sealing face.

5. Pump arrangement as claimed in claim 3 wherein said lower portion of said housing means has a housing space in which said manually operable means and said lower end of said support tube are located, said housing space being filled with the liquid when said closure means is closed and said shaft means is in said operative position; wherein said housing space has at least one large opening, and cover means closing said large opening when said housing space is filled with said liquid; and wherein, when said cover means is detached after emptying of said housing means and housing space by discharge of the liquid, said manually operable means can be operated through said large opening.

6. Pump arrangement as claimed in claim 5 wherein said shaft means includes detachable first connector means for onnectin said upper and lower shaft portrons, said 1rst conn ctor means being located in sald housing space accessible through said large opening for detachment; and wherein said housing means includes second connector means for connecting said upper and lower housing portions, and being operable for separating said upper and lower housing portions so that said lower housing portion with said motor and said lower shaft portion can be removed for service after said upper and lower housing portions, and upper and lower shaft portions have been separated by opening of said first and second connector means.

7. Pump arrangement as claimed in claim 5 comprising threaded means for connecting said upper housing portion with the lower end of said support tube, and located in said housing space for unscrewing through said opening so that said support tube with said upper shaft portion clamped to the same can be removed through said container in upward direction for service after emptying of said housing space.

8. Pump arrangement-as claimed in claim 5 wherein said lower end of said lower housing portion has a discharge opening located adjacent said holding means when the same is secured to said lower housing portion; and comprising a cooling conduit including cooling means connecting said discharge opening with said housing space when the same is closed by said cover means so that the liquid circulating about said motor is cooled; and a normally closed discharge valve connected with said cooling conduit, so that when said holding means and cover means are detached, the liquid in said housing means can be discharged through said discharge opening and opened discharge valve.

9. Pump arrangement as claimed in claim 9 wherein said cover means of said housing space has an opening to which said cooling conduit is connected.

10. Pump arrangement as claimed in claim 1 wherein said holding means includes a cover, and screws for securing said cover to said lower end of said lower housing portion so that said shaft means is supported in said operative position by said cover. 

1. Reactor liquid circulating pump arrangement comprising: a reactor container for a radioactive cooling liquid; housing means filled with said liquid, said housing means including a lower housing portion, and an upper housing portion secured to said container, and a support tube projecting upward into said container and having a first annular sealing face in said container; shaft means mounted in said housing means for rotation and also for limited axial movement, said shaft means including an upper portion located in said support tube and having an end portion projecting from said support tube and including a pump wheel located in said reactor container for moving said liquid, said end portion having a second annular sealing face located above said first sealing face, said shaft means having a lower shaft portion located in said lower housing portion of said housing means; a motor in said lower portion of said housing means acting on said lower shaft portion for rotating said shaft means; and holding means detachably secured to the lower end of said lower housing portion and supporting the lower end of said lower shaft portion in an operative position in which said first and second sealing faces form a gap for communication of the liquid in said reactor container with the liquid in said housing means for cooling said motor, said shaft means dropping to a lower inoperative position when said holding means is withdrawn so that said second sealing face abuts said first sealing face and communication between said reactor container and said housing means is interrupted whereby the liquid filling said housing means can be discharged therefrom without discharge of liquid from said reactor container.
 2. Pump arrangement as claimed in claim 1 wherein the lower end of said carrier tube has a first abutment surrounding said shaft means; wherein said shaft means has a second abutment below said first abutment; and comprising clamping means operable for forcing said abutments apart when said shaft means is in said inoperative dropped position so that said second sealing face is pressed against said first sealing face.
 3. Pump arrangement as claimed in claim 1 comprising manually operable means in said housing means acting on the lower end of said support tube and on a part of said upper shaft portion adjacent the same for urging said shaft means downward so that said secoNd sealing face is clamped against said first sealing face.
 4. Pump arrangement as claimed in claim 3 wherein said lower end of said support tube has a thread, wherein said part of said upper portion of said shaft means includes an annular abutment, and wherein said manually operated means includes a threaded sleeve surrounding said upper shaft portion, and threaded into said thread of said support tube, said sleeve being turnable to a position abutting said annular abutment in said inoperative position of said shaft means so that said shaft means is clamped to said support tube while said shaft means is in said inoperative position and said second sealing face is pressed against said first sealing face.
 5. Pump arrangement as claimed in claim 3 wherein said lower portion of said housing means has a housing space in which said manually operable means and said lower end of said support tube are located, said housing space being filled with the liquid when said closure means is closed and said shaft means is in said operative position; wherein said housing space has at least one large opening, and cover means closing said large opening when said housing space is filled with said liquid; and wherein, when said cover means is detached after emptying of said housing means and housing space by discharge of the liquid, said manually operable means can be operated through said large opening.
 6. Pump arrangement as claimed in claim 5 wherein said shaft means includes detachable first connector means for connecting said upper and lower shaft portions, said first connector means being located in said housing space accessible through said large opening for detachment; and wherein said housing means includes second connector means for connecting said upper and lower housing portions, and being operable for separating said upper and lower housing portions so that said lower housing portion with said motor and said lower shaft portion can be removed for service after said upper and lower housing portions, and upper and lower shaft portions have been separated by opening of said first and second connector means.
 7. Pump arrangement as claimed in claim 5 comprising threaded means for connecting said upper housing portion with the lower end of said support tube, and located in said housing space for unscrewing through said opening so that said support tube with said upper shaft portion clamped to the same can be removed through said container in upward direction for service after emptying of said housing space.
 8. Pump arrangement as claimed in claim 5 wherein said lower end of said lower housing portion has a discharge opening located adjacent said holding means when the same is secured to said lower housing portion; and comprising a cooling conduit including cooling means connecting said discharge opening with said housing space when the same is closed by said cover means so that the liquid circulating about said motor is cooled; and a normally closed discharge valve connected with said cooling conduit, so that when said holding means and cover means are detached, the liquid in said housing means can be discharged through said discharge opening and opened discharge valve.
 9. Pump arrangement as claimed in claim 9 wherein said cover means of said housing space has an opening to which said cooling conduit is connected.
 10. Pump arrangement as claimed in claim 1 wherein said holding means includes a cover, and screws for securing said cover to said lower end of said lower housing portion so that said shaft means is supported in said operative position by said cover. 